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Amount of revenue not yet earned and included within the future policy benefits, other policy-related balances and policyholder dividend obligations.

No definition available.

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Carrying (unamortized) amount as of the balance sheet date of deferred policy acquisition costs and value of business acquired (also called present value of future profits).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35755530&loc=d3e11264-158415

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.7)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
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-Section S99
-Paragraph 2
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The liability as of the balance sheet date to the policyholders for deposits held under the terms of insurance contracts.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.13(a)(3))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 30
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-URI http://asc.fasb.org/extlink&oid=49168914&loc=d3e13951-158433

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Carrying value as of the balance sheet date of the liability for dividends that are payable to the policyholders based upon the terms of the underlying insurance contracts.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.14(a))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-URI http://asc.fasb.org/extlink&oid=6483535&loc=d3e16392-158451

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Amount of premiums not yet earned.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 235
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-16)
-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574960-122915

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

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Data Type:	na
Balance Type:
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Name:	us-gaap_StatementBusinessSegmentsAxis=met_GroupVoluntaryAndWorksiteBenefitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_StatementBusinessSegmentsAxis=met_CorporateBenefitFundingMember
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Data Type:	na
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Name:	us-gaap_StatementBusinessSegmentsAxis=met_LatinAmericaSegmentMember
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Name:	us-gaap_StatementBusinessSegmentsAxis=met_AsiaSegmentMember
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Name:	us-gaap_StatementBusinessSegmentsAxis=met_EuropeMiddleEastAndAfricaSegmentMember
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